The invention relates to an apparatus for mixing two flowing media, for mixing water and beverage concentrate or the like in particular, with a first passage channel passing through a housing from an inlet to an outlet and at least one second passage channel ending in said first passage channel, wherein a first medium, a fluid in particular, flows in said first passage channel and a second medium, a fluid in particular, flows in said second passage channel.
Mixing apparatuses of the above-mentioned kind are used for mixing beverages in particular, in that a concentrate, e.g. a fruit juice concentrate, is added to the basic liquid water in a given mixing ratio short before serving the beverage. The water can be conditioned, e.g. enriched with mineral substances or carbon dioxide, or cooled beforehand or can be taken directly from the water mains, wherein it is supplied with standard water pressure of appx. 1.5 to 2 bars to the apparatus for mixing.
For the production of such mixed beverages from concentrated liquid and water the use of a mixing apparatus is known which is passed by water in the manner of a Venturi nozzle and sucks in a concentrate from a bore merging at a right angle. By sucking-in of the concentrate, a concentrate/water mixture is obtained on the outlet of the apparatus. The mixing ratios in this mixing apparatus, however, can only be adjusted by different cross-sections of the channels, i.e. the mixing apparatus must be exchanged for making available another mixing ratio. This is very expensive, as high demands to hygienics are set for delivery of beverages.
Furthermore, in the known mixing apparatus the problem arises that the minimum cross-section of the channel for the concentrate is limited, if concentrated fruit juice containing fruit pulp is to be mixed, As the fruit pulp pieces have to fit through the cross-section in order not to block it, said cross-section must have a certain minimum size. This, however, results in that in traditional mixing apparatuses such fruit juice cannot be made available in low concentration.
A further problem in the known mixing apparatuses lies in that the concentrates may have different viscosities or viscidity which also is influenced by the different ambient temperatures in particular, such that different mixing ratios are obtained in case of different conditions. In the known mixing apparatuses there is no possibility for simple and cheap regulation of the mixing ratio.
The invention, therefore, is based on the object of improving an apparatus of the kind cited in the beginning such that the mixing ratio between two flowing media, between water and a beverage concentrate in particular, can be adjusted in simple manner, wherein this is to be possible independently from the concentrate composition, i.e. containing few or many solid matter portions, with high or low viscosity or the like. Furthermore, the mixing apparatus is to be manufacturable in cheap manner and guarantee safe function also in intermitting operation.
This object is solved in advantageous manner in that at least one by-pass channel to said first passage channel and a means for setting the passing amount of said first and/or second fluid is provided for. In this manner, an arbitrary mixing ratio for the two fluids can be set in simple manner independently from the viscosity and/or the problem, respectively, the fruit pieces are contained in the concentrate. In particular, the second passage channel merging into said first passage channel can have a comparatively large cross-sectional are so that the solid matter particles of the beverage concentrate can uninhibitedly flow through the cross-section, as the mixing ratio only in limited manner depends on the cross-section of the second passage channel. For setting the mixing ratio the mixing apparatus need not be exchanged, so that when changing the mixing ratio no hygienic problems due to the use of a new apparatus are created either. If another concentrate is to be used with the same apparatus, the apparatus due to its simple construction can also be easily cleaned, this being dealt with lateron.
In preferred embodiment of the invention, by the means for setting the passing amount either the passing amount of the first fluid and/or or the second fluid can be adjusted. As in beverage mixtures said first fluid mostly is formed by water and the main portion of the mixture consists of water, the mixing ratio can be varied in a very broad area. Preferably, therein the passing amount of said first fluid is adjustable using the bypass channel and/or bypass channels, so that one could do without a setting means in the merging area of the second passage channel in said first passage channel. The junction could therefore be built in constructively simple manner, while the mixing ratio in practice is regulated over the bypass channels directly. When said second passage channel enters said first passage channel essentially perpendicularly, in the area of entry defined and calculable flow conditions are provided for which are similar to those in Venturi nozzles. In advantageous manner, however, also in the second passage channel a setting means can be provided for which permits fine adjustment of addition of concentrate in particular then if concentrates with low or no solid matter portion, e.g. tee, lemon concentrate or the like, are used.
In further preferred embodiment of the subject matter of the invention it can be provided for that said first passage channel comprises an entry region a central section and an exit region, said central section having a smaller passage cross-section than said entry region and said exit region. In this way it is achieved that in said central section an increased flowing velocity prevails. Said central section therein is made very short as compared to said entry region and said exit region, wherein it e.g. has an extension of only 1.5 to 2 mm, whereas said entry region can amount to approximately 25 mm and said exit regionxe2x80x94to approximately 40 to 50 mm. In said entry region in addition a relief chamber is formed in which essentially equal pressure is prevailing. Thereby, variations in pressure and/or in the passing amount of the first fluid, respectively, can be balanced. In the area of its free end said first passage channel preferably comprises an increasingly widening cross-section, this slowing down the initial acceleration of the flow and thus reducing formation of whirls.
Said second passage channel through which the beverage concentrate is supplied preferably enters downstream of said small passage cross-section and essentially perpendicularly into said first passage channel. The junction is located comparatively close to said central narrowed section of said first passage channel such that fruit juice concentrate is entrained by the accelerated water flow and, therefore, no supply of concentrate under pressure is required.
In order to be able to dose the mixing ratio, the bypass channel or channels extend from the entry region of said first passage channel to the exit region and have an essentially constant cross-section. They extend in parallel to the central section of said first passage channel, with its upstream end entering the relief chamber and with its downstream end with a distance to the jonction of said second passage channel entering into the exit region of said first passage channel. Therein, the jonction of each bypass channel is arranged with sharp angle to the axis of said first passage channel and is formed by a piercing bore which has a cross-section narrowing like a nozzle. In same manner the jonction of said second passage channel into said first passage channel can be formed. For setting the passing amount of the fluid through the bypass channels and/or said second passage channel, respectively, dosing means can be provide for which are insertable into the jonction openings. Said dosing means in advantageous manner can be formed by pins which are formed with a tip adapted for being seated in the jonction opening and which are guided in cross bores adjustably by means of a fine thread. By means of the dosing means by which the opening cross-section of the bypass channel or the bypass channels as well as the opening cross-section of said second passage channel can be regulated, the mixing ratio can be arbitrarily set in simple manner. Even if the passage cross-section of said second passage channel has to be opened essentially fully for permitting passage of a larger fruit pulp amount, dosing is possible without problems through the adjustable bypass channels by accurately controlling the passing amount through the respective bypass channel.
In order to manufacture the mixing apparatus as favorable in terms of costs as possible, the housing of said mixing apparatus preferably is made from plastic material and is formed as one-piece injection-molded body. The housing can comprise a fixation means and in the area of the free channel ends connecting necks for connection of connecting hoses, concentrate reservoirs, fluid inlets and/or the like. The connections therein can in known manner be formed as rapid action coupling connections which interlock with respective grooves of the housing and whose connection can be sealed by an O-ring seal e.g. It also is conceivable that in the hose connections closing means are provided for which close the flow to the connecting end of the hose before a corresponding flowing connection to the apparatus in accordance with the present invention is established. Additional closing means can be formed at the inlet side of the apparatus itself for preventing backflows from one channel into another channel.